Think Different: The Tillage Trap

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Most farmers like tillage. Soil really doesn't like it. Too deep or poor timing is simply bad for its health. And this year, given the drought, you lose valuable soil moisture and clog soil pores.

I pondered tillage during a mid-October drive between Minneapolis and Des Moines. Most years at this time, harvest would still be in full swing, but this year almost all fields I saw during windshield time were tilled. Already. Done.

Given this early tillage trend, university soil scientists have reminded farmers that each tillage pass can reduce plant-available water by 0.75 in. Not only that, it clogs soil pores. Then raindrops break soil aggregates to further slow water infiltration to increase surface runoff. Then subsequent rains result in more runoff due to crusted soils. Such a cycle of challenges create a tillage trap, as farmers see a need to continue this trend.

In this issue, you'll see how a Persia, Iowa, farm couple stopped their tillage trend 12 years ago (starts on page 14) when they began to implement a stellar soil saving no-till system in their hills to help combat extreme rain events. Bill and Babetta Lucke'sestablished no-till fields have better erosion resistance and better water infiltration than minimum-tilled fields. Bill’s side-by-side yield trials for three years before he switched found no yield differences at all. In a good year, his soils are capable of producing 190-210-bu. corn and 50-60-bu. soybeans.

We've all seen more severe rainstorms over the last five years, 2012 aside. And in a driving rainstorm, raindrops can hit the ground at 20 mph, sending soil particles as high as 4-5 ft.

While we can't stop severe weather events, we can improve our farms, field by field, to not only save soil but to improve soil biology. And I know it takes a partnership with landlords who care.

Inside another story, "Soil Wealth" (pages 28-29), we highlight how North America is blessed with a disproportionate share of the world's best agricultural soil. Unfortunately, as author David Montgomery found, tilled soils erode 10 to 100 times faster than soil forms. Every year, about 0.5% of the world's arable land is degraded enough to be taken out of production.

To this end, across the Corn Belt, 70% of highly erodible cropland (HEL) – more than 14 million acres – is losing soil faster than the NRCS’ tolerable rate of 5 tons/acre/year, according to the 2007 NRCS National Resources Inventory.

If you have fields you can improve, I hope you can work with your landlord and build more sustainable fields together.

I sincerely thank you for reading and for being willing to Think Different.